PHILADELPHIA (CBS) — Losing and gaining weight is a weekly cycle for most people, according to new research that reveals a pattern for slim success. 3 On Your Side Health Reporter Stephanie Stahl explains.

What’s your weekend indulgence? Pizza, a couple of extra drinks or homemade sweet treats? New research from Cornell University confirms weekend pig outs are common.

“Every person in the world ends up weighing more Sunday night,” said Professor Brian Wansink, who wrote the book “Slim By Design” and conducted the Cornell study. It found there are weekly weight cycles. People tend to gain weight over the weekend then lose it during the week.